Dumaguing: Glaucoma and blindness
MARCH 13-18 is World Glaucoma Awareness Week and based on 2010 statistics, 60 million suffer from glaucoma worldwide with 3.5 million are Filipinos and about 55 percent of them are women.
We just welcomed 2017 and therefore the glaring reality is obviously, there are now more people afflicted with vision malady.
Glaucoma is a disorder in which the pressure inside the eyes--IOP or intraocular pressure--increases damaging the optic nerve and causing loss of vision. Please allow your columnist to establish some basic data about our eyes. All objects we see send light rays unto our eyes which are then bent or refracted by four structures- first the cornea, and then crystalline lens- strongest capacity to refract, then aqueous humor and the vitreous humor- gel like substance that provides the bulk of the eyeball. With the aforementioned structures working together, those rays of light entering the eye will have a principal focus on the retina of the eye, which conveys a nerve impulse to the optic nerve which carries the impulse all the way to the calcarine gyrus, so-called Visual center at the occipital lobe which the object seen gains meaning, that is, perceived as to what it is, its size, shape, color it's three dimension,- length, width and thickness/breadth and whether the object seen is moving or stationary.
The human eye has been layered into is fibrous coat- the cornea and sclera; the uveal tract- lens, iris- its pigments determine the color of one's eyes, an aperture - pupil, the lens- the front of which is called anterior chamber while behind it is the posterior chamber and the innermost layer, also considered the nervous layer and probably the most delicate is the retina which has our receptor for light/darkness as well as perception of colors- its shades and hues.
Both the front (anterior chamber) and back (posterior chamber) of the eyes are filled with a thin, watery clear liquid called aqueous humor, which is continuously secreted by the ciliary process of the eyes. Its drainage originates from the posterior chamber then unto the papillary opening unto the anterior and exits thru the canal of Schlemm to join the veins of the eyes and later general circulation. Glaucoma comes in two forms: if the outflow chamber is blocked or obstructed, then it is called closed-angle glaucoma, if it is outflow chamber is patent, and then it is called open-angle glaucoma. Again, there are more sufferers from closed-angle glaucoma and sad to say, is the leading cause of non-reversible glaucoma.
Glaucoma has a very strong genetic predisposition meaning that if one has a relative who has glaucoma, the risk of having glaucoma is 10 times.
Nearsighted folks or those who suffer from myopia with more than - 500 visual acuity Snellen's test are also more likely to suffer from glaucoma- the most common presenting deficit is peripheral vision in which the person does not see much from the side of his eyes, later blurring of vision, headaches. Of course, those who have unchecked diabetes mellitus or wayward hypertension are also at risk.
Diagnosis may be from the very basic tonometry to measure intraocular pressure, gonioscopy to visualize the angle openings of the canal of Schlemm, perimetry, slit lamp and other high tech gadgets which , your columnist is delighted to inform our dear readers and friends as well as patients , found in the clinics of trained and skilled ophthalmologists and comprehensive eyes specialists like among which are Drs. Aldo Mar Cariaga, Dan Flores, Noel Sison- true-blue Baguio boys whose expertise in eye care is as good as their peers in the bigger cities in the Philippines. Seek them out and their colleagues in our beloved city. As the song goes, “on a clear day, you can see forever." That is, with healthy eyes.